AN INTRODUCTION TO Faster fusion What is fusion? That is, the tokamak is a toroidal – or ring- PROGRESS IN FUSION HAS SLOWED Can we achieve fusion faster? Additionally, high temperature Fusion is the energy of the stars. Small atomic nuclei join together to make larger ones, doughnut-shaped – vessel with magnetic We believe so. In the last few decades new superconductors can support a much which releases energy. All the heavier elements in the universe were made this way. coils that make a trap for the plasma. The Moore’s Law technologies have emerged. Building on all higher current density than conventional plasma is heated using microwaves or (computers) the work that has gone into JET and ITER, it superconductors (meaning they can achieve Fusion only happens at very high temperatures because it is forcing together particles that powerful particle injectors and it has to be Fusion energy gain now seems feasible that by using a slightly higher magnetic fields for the same thickness would usually be far apart. Nuclei are all positively charged particles, so they keep away stabilised by carefully controlling the shape of differently shaped (spherical) tokamak of superconductor), so they will work with the from each other just like magnets of the same polarity repel. Nuclei don’t want to come the magnetic fields. Progress combined with the latest generation of high squashed-up shape of the spherical tokamak. toward fusion together, so the only way for fusion to occur is to heat things up a lot, like in the stars. temperature superconductors for magnets, we HTS magnets will be a game-changer for When will we be using fusion power? could make smaller, cheaper machines and so fusion, but scaling up requires new systems That is the hardest question to answer. Tokamak make progress faster. and techniques. experiments Why do we care? Research started in the 1950s and the big worldwide The world needs a base-load power source joke is that fusion is 30 years away… and What is a spherical tokamak? Our recent work (Costley et al, Nuclear Fusion, 1965 1975 1985 1995 2005 2015 that is abundant, safe and CO2-free. Fusion is always will be. We don’t think that’s true. We A spherical tokamak is one that is squashed up 2015/2016) shows that smaller, cheaper one of the few options we have. think faster fusion is possible, but it is harder The answer lies in the physics. The fusion so it looks more like a cored apple than a ring tokamak fusion reactors are possible. In than was originally thought. Globally, tens of power we get out depends on the efficiency doughnut. It therefore makes more efficient use principle we could attain similar fusion How could we make the energy of thousands of people are working on it – and of the machine, the strength of the magnetic of the high magnetic field at the centre. performance to an ITER-scale device at only the stars on Earth? making progress – but it takes time, money, field and the size (volume) of the toroidal about 1/20th the volume. We are working on First it involves heating our fuel to hotter than new materials and technology, and intelligent vessel: What is a High Temperature determining the optimum size and design for the centre of the Sun – over a hundred million new minds coming into the field to solve the Superconductor? a future fusion reactor. 2 4 degrees. At these temperatures, the electrons puzzle of how to create fusion power on Earth. A superconductor is a material with zero ×BT×V of atoms break away from their nuclei to electrical resistance when it is extremely We advocate a modular approach to fusion. It create a soup of very fast-moving, electrically- When developing new technologies and Back in 1985, when engineers were designing cold, so it doesn’t heat up when current flows may not be necessary to generate the highest charged particles called plasma. Somehow expertise, timescales are difficult to predict. the next tokamakP∝ afterβ JET, the efficiency of through. Conventional superconductors are absolute fusion power. What is important is we have to confine this, or trap it, so that we But Tokamak Energy aims to demonstrate the machines and the magnetic field strength cooled by liquid helium to -269C (or 4K). High the fusion gain (ratio of power out to power can keep the fuel hot enough for long enough First electricity from fusion by 2025 and were limited by the technology of the time. Temperature Superconductors (HTS) become in), or rather how much extra energy we can for fusion to occur. Different methods have commercially viable fusion power by 2030. Increasing size seemed the only way forward. superconducting at a higher temperature, get out. Using several low-power machines been proposed and the main contenders are: The world agreed to construct the giant ITER around the boiling point of liquid nitrogen with high gain may be better than using one inertial (or laser) fusion, which uses lasers to Why has it taken so long? tokamak in France. Feats of engineering at -196C (77K). That’s still rather cold, but it big, high-power machine, and it also gives heat and confine the fuel; or magnetic fusion, Did you know that scientists have actually such as this take time. Construction is now represents a big saving in cooling energy. more flexibility to the power station operator. which uses magnetic fields. achieved fusion? Unfortunately, so far they well underway but ITER won’t be operating have put more energy in to do it than they for several years yet – probably mid-to-late How can these help fusion? Within the field of magnetic fusion, the got out. The JET tokamak in the UK holds the 2020s. Spherical tokamaks can generate higher tokamak machine is the most developed and world record for fusion power. In 1997 JET plasma pressure for a given magnetic field. best understood. made 16MW – about 65% of what was put in Also, plasma physics is very complicated. In other words, they have a higher efficiency to heat the plasma Keeping hot plasma trapped requires a good than conventional tokamaks. High What is a tokamak? understanding of how it behaves. With all the temperature superconductors can give higher The word “tokamak” is a Russian acronym Progress towards fusion power was rapid for research over the past decades, physicists magnetic field and better performance than that stands for “toroidal chamber magnetic 30 years – slightly faster than Moore’s law are now in a better position to improve the conventional ones. Combined, it is possible to coils”. for computers. But has slowed since the JET performance of fusion plasmas. achieve fusion power without increasing the achievement in 1997. Why? machine size so much. A faster way to fusion What is Tokamak Energy doing to HTS Magnet Demonstrator - This will be a tokamakenergy.co.uk solve the problem? full-scale high temperature superconducting Tokamak Energy Ltd is a private company magnet designed for high-field tokamak @TokamakEnergy based at Milton Park, Oxfordshire, and funded operation. by investors. In collaboration with leading @tokamakenergy industrial and academic partners, our team An HTS tokamak combining of world-class fusion scientists and magnet knowledge gained from previous milestones TokamakEnergy engineers aims to achieve commercial to generate industrial scale fusion power and fusion by breaking the challenge down into demonstrate net energy gain. Another world engineering milestones: first for us! Small experimental tokamak with This will be the first fusion power conventional copper magnets. It was used plant module. It will produce over 150MW to develop capabilities crucial for reactor and could be used alone or as part of a “farm” operation and can be operated remotely. of modular devices. The world’s first tokamak with For the future we see a modular series of high temperature superconducting (HTS) such 100-200 MW power plants. These could magnets. It pioneered this new technology be manufactured to a standard design and and held a plasma for 29 hours in 2015. shipped around the world. The world’s first high-field spherical Are we nearly there yet? tokamak (>2 Tesla). It has copper magnets We are getting closer. It is now acknowledged and will verify theoretical predictions as well that the spherical tokamak design with as reaching plasma temperatures of 100 HTS magnets offers the smallest, most million degrees by the end of 2018. cost-effective solution. This is our solution. Yet there are many complex engineering challenges that need to be overcome for demonstration and commercialisation of fusion. Our unique approach is centred on rapid innovation using the latest materials and technology, but building on decades of scientific research and experience. Once fusion electricity is achieved, our scalable technology could be rolled out across the world as a solution to one of humanity’s Milton Park greatest challenges: clean and sustainable Oxfordshire energy for all, for thousands of years into the future. Telephone: +44 (0)1235 355940 This strategy gives us – and the Email: [email protected] world – a faster way to fusion..